Shuffle Bed

shuffle-bed

Quick Start

• Command: shuffleBed -i intervals.bed -g genome.txt [options]
• Local executable: /home/vimalinx/miniforge3/envs/bio/bin/shuffleBed
• Full reference: See references/help.md

When To Use This Tool

• Randomize interval locations to build null models for enrichment or overlap testing.
• Preserve original interval lengths while relocating them within a genome.
• Restrict random placement with inclusion or exclusion masks.
• Keep intervals on the same chromosome or enforce non-overlap among shuffled results.

Common Patterns

# 1) Basic genome-wide shuffle
shuffleBed \
  -i peaks.bed \
  -g genome.txt > peaks.shuffled.bed

# 2) Reproducible same-chromosome shuffle excluding blacklist regions
shuffleBed \
  -i peaks.bed \
  -g genome.txt \
  -chrom \
  -excl blacklist.bed \
  -seed 42 > peaks.shuffled.bed

# 3) Shuffle only within allowed regions
shuffleBed \
  -i peaks.bed \
  -g genome.txt \
  -incl accessible_regions.bed \
  -maxTries 10000

Recommended Workflow

1. Decide whether the null model should preserve chromosome identity (-chrom) or allow genome-wide relocation.
2. Add -seed whenever the shuffled set must be reproducible.
3. Use -incl, -excl, -noOverlapping, and -maxTries to match the biological constraints of the null model.
4. Check that the shuffled output preserved record count and interval length distribution before using it for inference.

Guardrails

• -i and -g are required.
• -incl disables -chromFirst.
• -f can be used with -excl but not with -incl.
• -chrom forces same-chromosome placement and also forces -chromFirst.
• -allowBeyondChromEnd changes the interval-length preservation rule near chromosome ends, so only use it intentionally.